1. Technical Field
The technical field relates to a printing head module, and more particularly to a printing head module having a wiper unit.
2. Description of Related Art
With advancement in computer-aided manufacturing (CAM), a three dimensional printing technology (3-D printing technology) has been developed in the manufacturing industry, thereby rapidly fabricating products from an original design concept. The 3-D printing, in fact, is a general term of a series of rapid prototyping (RP) techniques, and the basic principle thereof, and the concept thereof is a laminate manufacturing, wherein a rapid prototyping machine is used to form cross-sectional shapes of a workpiece in the X-Y plane through scanning, shift intermittently at a layer thickness in the Z coordinates, and ultimately form 3-D objects. The 3-D printing technology is unrestrictedly applicable for the geometric shapes and the RP technology produces excellent outputs in particular for complex parts, which saves efforts and processing time significantly. As a result, the digital 3-D printing technology is capable of presenting an object of a digital 3-D model designed by means of computer-aided design (CAD) software under a shortest time requirement for the user to touch and actually feel the geometry of the model, or even to do possible functional test thereof.
When a printing head module is disposed with a plurality of printing heads, the printing heads are alternatively operated during the 3-D printing process. However, as the printing head is switched from one to another, often there is still residual modeling material left on the nozzle tips of the printing head which just finishes the printing task. Accordingly, the residual modeling material left on the nozzle tips of those printing heads might drop on the printing surface, which cause the contamination issues on the printing objects. Therefore, the printing quality of the 3-D printing process with multiple printing heads is decreased.